Mobil Tyco Solar Energy Corporation

Mobil Solar Energy Corporation

Douglas A Yates

Arthur E Hatch

Jeff M Goldsmith

Jack I Hanoka

Ronald C Gonsiorawski

James A Gregory

A solar cell fabrication procedure is described which is characterized by (1) forming a front surface mask in the configuration of the front surface electrodes, (2) a passivation step which, inter alia, results in the formation of an altered silicon substrate surface layer in the areas not covered by the front surface mask, (3) removal of the front surface mask, and (4) the use of the altered surface layer as a plating mask for subsequent metallization steps.

Method of fabricating solar cells

A solar cell fabrication procedure is described which is characterized by (1) removal of the front surface electrode plating mask after preliminary metallization of the front surface electrodes, (2) a passivation step which, inter alia, results in the formation of an altered silicon substrate surface layer, and (3) use of the altered surface layer as a plating mask for subsequent metallization steps involving, for example, immersion plating of nickel and immersion plating or electroplating of copper.

A solar cell fabrication procedure is described in which a hydrogen ion passivation step is used to form, inter alia, an altered silicon substrate surface layer to which immersion plated nickel will not readily adhere. The altered surface layer is formed by shadow casting an ion beam in a pattern corresponding to the desired front surface interelectrode configuration.

The growth of a crystalline body of a selected material is controlled so that the body has a selected cross-sectional shape. The apparatus is of the type which includes the structure normally employed in known capillary die devices as well as means for observing at least the portion of the surfaces of the growing crystalline body and the meniscus (of melt material from which the body is being pulled) including the solid/liquid/vapor junction in a direction substantially perpendicular to the meniscus surface formed at the junction when the growth of the crystalline body is under steady state conditions. The cross-sectional size of the growing crystalline body can be controlled by determining which points exhibit a sharp change in the amount of reflected radiation of a preselected wavelength and controlling the speed at which the body is being pulled or the temperature of the growth pool of melt so as to maintain those points exhibiting a sharp change at a preselected spatial position relative to a predetermined reference position. The improvement comprises reference object means positioned near the solid/liquid/vapor junction and capable of being observed by the means for observing so as to define said reference position so that the problems associated with convection current jitter are overcome.

Method for crystal growth control

Apparatus for crystal growth control

A system for and method of growing a crystalline body of a selected material is described, whereby the body grown is of a selected cross-sectional shape. The system and method are used in accordance with known capillary die techniques and further includes observing opposite edge portions of the growing body, preferably just above the meniscus (of melt material from which the body is being pulled). The cross-sectional size of the growing crystalline body can be controlled by determining when horizontal shifts occur in the edge portions relative to each other as well as the same predetermined reference position.

Method and apparatus for crystal growth control

Apparatus is disclosed for controlling the growth of a crystalline body of a selected material so that the body has a selected cross-sectional shape. The apparatus includes the structure normally employed in known capillary die devices and further includes means for observing at least the portion of the surfaces of the growing crystalline body and the meniscus (of melt material from which the body is being pulled) including the solid/liquid/vapor junction in a direction substantially perpendicular to the meniscus surface formed at the junction when the growth of the crystalline body is under steady state conditions. The cross-sectional size of the growing crystalline body can be controlled by determining which points exhibit a sharp change in the amount of reflected radiation of a preselected wavelength and controlling the speed at which the body is being pulled or the temperature of the growth pool of melt so as to maintain those points exhibiting a sharp change at a preselected spatial position relative to a predetermined reference position.

Apparatus for controlled growth of silicon and germanium crystal ribbons

A method is disclosed of growing a crystalline body of a selected material so that the body has a selected cross-sectional shape. The method includes the steps normally employed in known capillary die processes and further includes observing at least the portion of the surfaces of the growing crystalline body and the meniscus (of melt material from which the body is being pulled) including the solid/liquid/vapor junction in a direction substantially perpendicular to the meniscus surface formed at the junction when the growth of the crystalline body is under steady state conditions. The cross-sectional size of the growing crystalline body can be controlled by determining which points exhibit a sharp change in the amount of reflected radiation of a preselected wavelength and controlling the speed at which the body is being pulled or the temperature of the growth pool of melt so as to maintain those points exhibiting a sharp change at a preselected spatial position relative to a predetermined reference position.

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Burlington, MA, United States of America

Douglas A Yates